RDMA/hns: Support STARS mode QP

driver inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8C2IP



--------------------------------------------------------------------------

STARS is a HW scheduler. QP in STARS mode will be taken over by STARS's
HW.

This patch supports configuring STARS mode QP. At the same time, a
kernel API rdma_query_qp_db() is provided for querying the QP DB address
taken over by STARS.

Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>